Fixing system for cables, in particular in wind turbines

ABSTRACT

The invention relates to a fixing system for cables, in particular in wind turbines, comprising a main body ( 1 ) that can be fixed to a supporting structure, and comprising cable holders ( 11 ) that have an opening for cables to be inserted, which opening can be closed by a cover device ( 45 ). The fixing system is characterised in that cable holders ( 11 ) in the form of components that can be mounted on the main body ( 1 ) are provided and are arranged on the main body ( 1 ) in an arrangement extending at least over a part of a ring with the opening of the cable holders on the outside, and in that the cover device comprises retaining elements ( 45 ), by means of which the opening of the respective cable holders ( 11 ) can be blocked to secure inserted cables.

The invention relates to a fixing system for cables, in particular in wind turbines, having a main body, which can be fixed to a supporting structure, and having cable holders, which have an opening for the insertion of cables, wherein said opening can be sealed by a cover device.

In order to discharge the energy generated in wind turbines as well as for other operational purposes such as control, monitoring and the like, cables, which run though the tower into the nacelle, must be reliably fastened to the appropriate supporting structures, in particular the tower segments. Fastenings with clamp-like main bodies, in which inserted cables can be secured, are typically used for this purpose. Fixing systems of this kind, in which a corresponding number of screwing procedures must also be carried out, require a high degree of assembly expenditure. This applies in particular to the fastening of cables, which must be routed from below, through the tower to the nacelle and connected to the generator unit. In the case of conventional wind turbines, this generator unit may need to be rotated together with the nacelle for up to three turns before the nacelle is steered back. In order for the cables to be able to make this movement as well, they are routed over a cable loop hanging in the tower. To prevent the cables from rubbing against one another during the rotational movements, the cables must be kept at a distance here. Cables are therefore typically held by means of a round supporting structure, for example in the form of a tubular piece, around which the cables are distributed and fastened using simple clamps. Mounting of this kind is costly and tedious.

In this respect, the object of the invention is to provide an especially suitable fixing system for the application in question.

This objective is achieved according to the invention by a fixing system comprising the features in claim 1.

Accordingly, an essential feature of the invention is that cable holders are provided in the form of components that can be mounted on the main body, and are disposed on the main body in an arrangement extending at least over a part of a ring with the openings of said cable holders on the outside, wherein the cover device has retaining elements, by means of which the opening of the respective cable holders can be blocked in order to fasten, in particular to pre-fasten, the inserted cables.

The annular arrangement of the cable holders allows the cables to be fixed in a cable loop hanging from the nacelle in the tower such that those cables are positioned and distanced from one another as in the tower segments themselves, so that chafing of the cables can be avoided in any event. The fact that further cable holders are provided in the form of components that can be mounted on the main body opens up the advantageous possibility of realizing a fixing system that can tolerate especially high loads with little design effort and at a low cost. In the case of separate cable holders that can be attached to the main body, different materials can be used for these cable holders and the main body. Thus cable holders can be efficiently and cost-effectively molded out of a plastic material, for example, while the main body can be formed as a metal structure, for instance in the form of a steel structure with a high degree of structural stability, i.e. it can be designed for optimal stability without having to forgo the use of cable holders made out of inexpensive materials. The fact that, according to the invention, retaining devices are also available as an element of the cover device, by means of which retaining devices the insertion opening can be blocked in order to pre-fasten the cables inserted into the cable guides of the cable holders, allows the cables to be readily inserted into the cable guides, one after the other, since they are secured against falling out.

Since the cover device preferably also has a band clamp, which exerts the retaining force on the cables by means of the retaining devices, only a single screwing procedure is needed to tension the band clamp in order to secure the total number of cables held in the annular arrangement. A retaining force can also be exerted on the received cables by means of the cover device if necessary.

In especially advantageous embodiments, the main body comprises a steel band, which is positioned between end sections that form attachment points for anchoring on the supporting structure, said steel band extending preferably as a part of an arc that forms a circular ring, along which a row of cable holders is mounted. This kind of steel supporting structure ensures that the cables are securely anchored even if the cable holders are made of a lower strength material such as plastic.

An overall structure with an especially high degree of stability can be achieved with embodiments, in which a cross-member in the form of an axis extending through the inside of the arc is provided, which penetrates the band of the arc on both sides between the end sections that serve as anchoring sites and the respective end of the row of cable holders and projects outward, wherein the projecting ends of the cross-member each form a point of application for the band clamp. Such a cross-member, in particular if it is welded to the band at the penetration points through the band, forms a particularly effective reinforcement of the arc that runs semicircularly, for example, so that a high degree of stability is assured with a low material cost. At the same time, due to the cross-member, points of application for the band clamp are available, to which the clamping force can be introduced into the structure with force components that predominantly run longitudinally with respect to the band and therefore with greater operational reliability.

In especially preferred embodiments, the cross-member is formed by a steel rod, the cross section of which is rectangular and the long side thereof, which extends in the circumferential direction of the arc, passes through a slot in the bracket band arc. In this arrangement, the clamping force of the band clamp is exerted in the direction of the long sides of the rectangular profile, thus in the direction of the greater bending resistance of the cross-member.

Each cable holder is preferably individually connected to the band of the main body and each has a trough-shaped cable guide.

It can be particularly advantageous if the arrangement is such that the cable holders have a curved base corresponding to the curvature of the band for installation on the band, and that a catch mechanism is formed between this curved base and the band, which secures the cable holders on the main body. Such a system is characterized by an especially low degree of installation effort.

The exact orientation of the cable holders on the band is very easy to achieve when the cable holders are disposed between positioning fittings, which extend radially in a row in the circumferential direction of the band from the circular arcuate band, and which engage with guide channels, which are formed by recesses in the side walls of the cable holders, in a fitted manner. The positioning fittings also serve to accept forces exerted between the cable holders and main body.

In especially preferred embodiments, the retaining devices are pivotably mounted on the edge of the opening of the trough-shaped cable guides of the cable holders in such a way that the retaining devices can be moved between an insertion position that can be turned away from the opening and a pre-fastening position securing the inserted cables, wherein a locking device, which secures the cable holders in the pre-fastening position, is provided between the cable holders and retaining devices. The retaining devices are secured to the respective cable holder by means of the pivotal mounting of said retaining devices on the cable holder so that they are non-detachable and need not be handled separately for each assembly process.

In especially advantageous embodiments, the retaining devices have a cover member, which is hinged on the cable holder and forms a support surface on its upper side for the band clamp, and a displaceable clamping member on the cover member, which is advanced by a spring , arrangement in the direction of the received cable. If necessary, a pre-clamping force can also be realized in such a way.

The invention is explained in greater detail below with reference to the drawings. These show:

FIG. 1 an oblique view in perspective of only the main body of an embodiment of the fixing system according to the invention, without cable holders attached to the main body;

FIG. 2 an enlarged and broken oblique view in perspective of a portion of the embodiment, wherein only one last cable holder and part of one preceding cable holder from a row of cable holders attached to the main body are visible;

FIG. 3 an enlarged and broken partial front view of the embodiment, wherein two successive cable holders are visible;

FIG. 4 a likewise enlarged and broken partial longitudinal section of the embodiment;

FIG. 5 a likewise enlarged oblique view in perspective of an individual cable holder;

FIG. 6 a sectional view in an enlarged scale as compared to FIGS. 2 to 5 of an individual retaining device for an embodiment of the invention and

FIG. 7 an oblique view in perspective similar to the view in FIG. 1 of the main body of a modified embodiment.

FIG. 1 separately shows the main body 1 of an embodiment to be described, without attached cable holders. The main body 1 is a steel structure comprising a steel band 3, which is bent into a semicircle between the end sections 5. At the end sections 5, angled brackets 7 with elongated holes 9 serve to anchor the main body 1 to a supporting structure. The brackets 7 are angled in relation to the end sections 5 to match the curvature of the tower wall in order to allow said brackets to be attached to the inner surface of a tower wall in wind turbines. In the present example, the arc of the band 3 extending between the end sections 5 forms the mount for eight cable holders, which are not shown in the depiction of the main body 1 in FIG. 1 for the sake of clarity, which are visible in FIGS. 2 to 5 however, where the cable holders are designated as 11. In order to attach the cable holders 11 to the band 3 of the main body 1, the band 3 has a fastening hole 13 so that each cable holder 11 can be attached equally spaced along the circular arc, said fastening hole 13 serving as a catch mechanism with the cable holder 11, in which a snap-in connection with a snap-in ridge 15 (FIGS. 4 and 5) is formed, which projects from the base 17 (FIG. 5) of the respective cable holder 11. As can be most clearly seen in FIG. 5, the base 17 has a curvature, which is adapted to the circular arc of the band 3. FIG. 4 shows the formed snap-in connection.

As shown in FIGS. 2 and 3, when the cable holders 11 are attached to the band 3, they lie with their side surfaces 19 (FIG. 5) flush with one another so that the cable holders 11 on the main body 1 form an uninterrupted arcuate row. As shown in FIG. 5, continuous recesses 21 are located in the side surfaces 19 of the cable holders 11 from the base 17 to the upper end, said recesses being formed in such a way that when the side surfaces 19 of two consecutive cable holders 11 lie flush against one another, positioning fittings can be appropriately accommodated in the recesses 21. Here, this involves cylindrical studs 23, which sit, are pressed, welded or glued in the stud holes 25 (FIG. 4) of the band 3, and which extend radially from the arc of the band 3. The recesses 21 in the cable holders 11 have an inner partial cylindrical surface 25 fitted to the studs 23. The positioning fittings may also have another cross-sectional shape.

As shown in FIG. 1, a cross-member 31 extends through the arc of the band 3 in the manner of a bowstring, said cross-member being formed by a steel rod having a rectangular cross section. This cross-member 31 passes through slots 33 in the band 3, and the end sections 35 thereof extend outward in a radial direction relative to the circular arc of the band 3. An anchoring point 37 for a respective end of the band clamp 39 is formed at the end sections 35 of the cross-member 31, said band clamp 39 encircling the row of cable holders 11; see FIGS. 2 and 3. The cross-member 31 is a steel rod having a rectangular cross section, and is guided in an orientation through the slots 33 of the band 3 such that the long sides of the rectangular profile face the circumferential direction of the band 3 and the cross-member 31 thereby counteracts the higher bending resistance of the tensile force of the band clamp 39 exerted in the circumferential direction. In the row of cable holders 11 disposed along the arc of the band 3, the two end section 35 of the cross-member 31 each replace the outer positioning studs 23 of the respective final cable holder 11. Adapted to the rectangular shape of these end sections 35, a further recessed groove 41 (FIG. 5), connecting to the partial cylindrical surface 25, is located in the respective recess 21 of the side surface 19 of the cable holders 11 at the bottom of the recess 21, into which the end section 35 of the cross-member 31 suitably engages.

As shown in FIGS. 1, 2 and 3, the band clamp 39, which can be tensioned by means of a turnbuckle 43 (FIG. 3) corresponding to the prior art, is in contact with the upper side of the retaining devices 45. The cable holders 11 each have a trough-shaped cable guide 47, which tapers towards the bottom of the trough and the upper end of which has an insertion opening for inserting the cable (not shown). The retaining devices 45 have a lower clamping member 51 below an upper cover member, which upper cover member forms the contact surface for the band clamp 39 on its upper side. In the operating state shown in FIGS. 2 and 3, this lower clamping member 51 extends over the insertion opening of the respective cable guide 47, exerting force on the inserted cables.

The retaining devices 45 have hinge plates 53 on one side of the cover member 49 thereof, with which the retaining devices can be pivoted, as on a hinge, on a swivel bearing 55, which is located on the cable holders 11 at the insertion opening thereof. Compared to the position shown in FIGS. 2 and 3, the retaining devices 45 can therefore be pivoted up into an insertion position, so that the cables can be inserted into the cable guides 47 before the band clamp 39 is applied, closed, and tensioned. Once the insertion process has been carried out at the respective cable holder 11, the retaining devices 45 are pivoted from the insertion position into a pre-fastening position on the cable holder 47. In this pre-fastening position, the retaining devices 45 can each be secured by means of flexible snap-in tongues 57, which are formed on the cover member 49 on the side opposite the hinge plates 53. These snap-in tongues 57 engage with snap-in tabs 59 on the cable holders 11. After the retaining devices 45 are thus pre-fixed, the band clamp 39 is guided over the cover members 49 of the retaining devices 45 and tensioned by means of the turnbuckle 53. If the retaining devices 45 can be held in a position, defined by a snap-in or other immobilizing connection, that closes or blocks the cable holders 11, in this case, it is possible, in one embodiment, not depicted here, for the band clamp to be omitted entirely.

FIG. 6 illustrates an embodiment of the retaining devices 45. Instead of forming these retaining devices as a one-piece component, for example as a molded part made of plastic, the retaining devices 45 can have a clamping member 51 that is relatively movable with respect to the cover member 49, as shown in FIG. 6. In this case, the clamping member 51 has the form of a rectangular plate, from the corner regions of which guide bars 63 extend in the direction of the cover member 49 and are guided so that they can be displaced in guide surfaces 65 in the cover member 49. A compound spring comprising multiple compression springs 67 is inserted between clamping member 51 and the cover member 49, which compression springs the clamping member 51 advances in the direction of the cable to their positioning. In order to limit the spring deflection, and to prevent the escape of the clamping member 51 from the formed spring case under the load of the compound spring, end stop projections 69 and 71 are provided on the guide 65 on the cover member 49 and on the guide bars 63 of the clamping member 51 respectively.

Thanks to the rigid steel structure forming the main body 1, the cable holders 11, the retaining devices 45, as well as the positioning studs 23, can be made out of a low cost material that allows efficient production, for example out of molded plastic.

FIG. 7 shows a separate depiction of the main body of a modified embodiment. In contrast to the above-described example, an alignment device is provided on the main body 1. This is provided in particular for applications in which the main body 1 is to be mounted on the inner wall of a conically formed tower segment in a wind turbine, said tower segment tapering in diameter to the nacelle so that the inner wall has a sloping gradient relative to the vertical. The orientation of the plane of the arc 3 can be aligned with the cable holders 11 in an orientation that is adapted to the respective wall inclination by means of this alignment device.

To this end, the alignment device has a cantilever 71 extending from the end sections 5 of the band 3 in the same respective direction, at the end of each of which a threaded sleeve 73 is located. An adjustment screw 75 located in each threaded sleeve 73, the free end 77 of which screw is supported on the inner wall of the tower segment in question, allows the desired position adjustment of the level of the arc 3 to be adjusted relative to the tower wall. 

1. A fixing system for cables, in particular in wind turbines, having a main body (1), which can be fixed to a supporting structure, and having cable holders (11), which have an opening for the insertion of cables, wherein said opening can be sealed by a cover device (45), characterized in that cable holders (11) are provided in the form of components that can be mounted on the main body (1) and are disposed on the main body (1) in an arrangement extending at least over a part of a ring with the openings of said cable holders on the outside, and in that the cover device has retaining elements (45), by means of which the opening of the respective cable holders (11) can be blocked in order to secure the inserted cables.
 2. The fixing system according to claim 1, characterized in that the cover device comprises a band clamp (39), which encircles the arrangement of cable holders (11) on the main body and secures the retaining devices (45).
 3. The fixing system according to claim 1 or 2, characterized in that the main body (1) comprises a steel band (3), which is positioned between end sections (5), which form attachment points (7, 9) for anchoring on the supporting structure, said steel band (3) extending preferably as a part of an arc that forms a circular ring, along which a row of cable holders (11) is mounted.
 4. The fixing system according to claim 1, characterized in that a cross-member (31) in the form of an axis extending through the inside of the arc is provided, which penetrates the band (3) of the arc on both sides between the end sections (5) that serve as anchoring sites and the respective end of the row of cable holders (11) and projects outward, and that the projecting ends (35) of the cross-member (31) each form a point of application (37) for the band clamp (39).
 5. The fixing system according to claim 1, characterized in that the cross-member is formed by a steel rod (31), the cross section of which is rectangular, and the long side thereof, which extends in the circumferential direction of the arc, passes through a slot (33) in the bracket band (3) arc.
 6. The fixing system according to claim 1, characterized in that each cable holder (11) can be individually connected with the band (3) of the main body (1) and has a trough-shaped cable guide (47).
 7. The fixing system according to claim 1, characterized in that the cable holders (11) have a curved base (17) corresponding to the curvature of the band (3) for installation on the band (3), and in that a catch mechanism (13, 15) is formed between this curved base and the band (3), that secures the cable holders (11) on the main body (1).
 8. The fixing system according to claim 1, characterized in that the cable holders (11) are disposed between positioning fittings (23), which extend radially in a row in a circumferential direction of the circular arcuate band (3) and engage with guide channels, which are formed by recesses (21) in the side walls (19) of the cable holders (11), in a fitted manner.
 9. The fixing system according to claim 1, characterized in that the retaining devices (45) are pivotably mounted on the edge of the opening of the trough-shaped cable guides (47) of the cable holders (11) in such a way that the retaining devices (45) can be moved between an insertion position that can be turned away from the opening and a pre-fastening position securing the inserted cables, and that a locking device (57, 59), which secures the cable holders (11) in the pre-fastening position, is pre-secured between the cable holders (11) and retaining devices (45).
 10. The fixing system according to claim 1, characterized in that the retaining devices (45) have a cover member (49), which is hinged on the cable holder (11) and forms a support surface on its upper side for the band clamp (39), as well as a displaceable clamping member (51) on the cover member (49), which preferably exerts a retaining force in the direction of the cable to be received by means of a spring arrangement (67). 